Successful treatment of MPO-ANCA–positive asthma with eosinophilic upper airway involvement using tezepelumab

Tezepelumab, a monoclonal antibody targeting antithymic stromal lymphopoietin, is an upstream biologic therapy for refractory airway inflammatory diseases, including severe asthma and uncontrolled chronic rhinosinusitis with nasal polyps (CRSwNP). However, evidence regarding its efficacy in patients with concomitant refractory eosinophilic inflammatory diseases involving both the upper and lower airways remains limited, particularly among those with elevated myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) levels. This case report describes a case of a woman with adult-onset severe asthma complicated by CRSwNP and eosinophilic otitis media, in whom tezepelumab demonstrated marked clinical efficacy. The patient developed refractory sinonasal and otologic symptoms that necessitated long-term oral corticosteroid therapy. Elevated MPO-ANCA levels were detected in the absence of clinical features suggestive of systemic vasculitis. Initiation of tezepelumab resulted in substantial improvement in upper and lower airway symptoms, accompanied by marked reductions in peripheral blood eosinophil counts and MPO-ANCA levels. Endoscopic and radiologic assessments demonstrated significant improvement in sinonasal and otologic findings, and oral corticosteroids were successfully discontinued within 20 weeks. At 52 weeks, complete resolution of otorrhea with closure of the tympanic membrane perforation was observed, and imaging confirmed improved aeration of the paranasal sinuses and middle ear. Sustained disease control has persisted for more than 2 years following treatment initiation, without symptoms of recurrence or re-elevation of MPO-ANCA levels. This case report suggests that tezepelumab represents an effective, steroid-sparing therapeutic option for severe asthma complicated by eosinophilic upper airway disease, even in the presence of MPO-ANCA elevation.